Burner for liquid or comminuted solid fuels



April 1934 G. B. VROOM 1,953,090

BURNER FOR LIQUID OR COMMINUTED SOLID FUELS Filed Nov. 17. 1931 INVENTORBY g a ATTORNEY 60:65:27 5. VeOoM 1 UNITED STA Patented Apr. 3, 1934BURNER FOR LIQUID OR COMIMINUTED SOLID FUELS (Granted under the act ofMarch 3, 1883,. as amended April 30, 1928; 370 0. G. 757) TES PATENTorrics This invention relates to a burner that is optionally usableforpowdered solid fuels or for liquid fuels, or both simultaneously.

It is the object of my invention to provide a burner that is equallyeffective for the combustion of either of the mentioned types of fuel,or of both together in case the calorific value of the solid fuel is lowor when rapid production of large quantities of steam is necessary, oreither the flame from the fluid fuel burner may serve merely as a torchto insure continuous ignition of the solid fuel in case the latter is ofvery low quality or is discontinuously fed.

A further object is to make the construction simple and rugged, cheap toproduce and easy to disassemble for inspection, replacement or repair.

With the above and other objects in view, the invention consists in theconstruction, combination and arrangement of parts as will behereinafter more fully described.

Reference is to be had to theacc'ompanying drawing forming apart of thisspecification in which like reference characters indicate corre- 5sponding parts throughout the several views and in which Fig. 1 is alongitudinal sectional view of the device;

Fig. 2 is an end elevation of the burner end 0 thereof;

Fig. 3 is a detail of the burner chamber with the device arranged foroperation by a motor connected to the shaft of the feed worm;

Fig. 4 is a longitudinal sectional detail of the shaft of the deviceadjacent the burner end thereof.

It is desirable that boilers be equipped to burn more than one type offuel, since at times it may be difficult or impossible to obtain onekind, or

0 a sufficiently good grade of that kind. Under such conditions, it maybe necessary to supplement or replace the solid fuel with liquid fuel,or vice versa. The present invention is designed to make possible suchchanges as expeditiously as 5 emergencies may require.

The body 5 is provided with a substantially cylindrical bore 6 in whichis mounted a feed worm '7 to which powdered solid fuel is delivered byfeed pipe 23. The shaft 8 of the worm passes through closure 9 for theouter end of the bore with thrust collars 10 and 11 on the shaftdisposed on opposite sides of the closure 9. Body 5 is shown asextending through a furnace wall comprising refractory lining 12 andshell 13.

i 5. In the inner end of body 5 is a mixing chamber 14 connected to anexpanding nozzle chamber 15 through a constricted throat. Air undersuitable pressure is supplied to wind-box 16 through-pipe 17 and isinjected through ducts 13 into the bore 6 adjacent the inner end of 0Worm 7, tangentially to the wall of the bore, wherebypowdered fueldelivered to the inner end of the worm is whirled with great turbulenceinto mixing chamber 14 and thence into nozzle chamber 15 where itignites. The turbulent movement of the air and fuel insures thoroughmixture thereof so that each particle of fuel is enveloped in air, thusmaking rapid and'come plete combustion possible. A stub shaft 19connected to theinner end of shaft 8 carries a propeller 20 that isrotated by the blast of air from ducts 18 to drive worm 7. Analternative drive for the worm is motor 21 connectible to shaft 8 by aclutch 22. 1

Liquid fuel under pressure is supplied to inter- 7 nally grooved collar24 by pipe 25, whence it passes through duct 26 in shaft 8 and stubshaft 19 to an atomizer 25 carried on the end of the stub shaft, asshown in Fig. l or on the end of shaftS as shown in Fig. 3. The liquidfuel may 3 be burned alone or simultaneously with the solid fuel by theconstruction shown in the first figure if the solid fuel alone does notdevelop suflicient heat, or the liquid fuel may be burned to serve onlyas a torch to ignite the solid fuel. Fig. 3 shows device adapted fordriving worm '7 by motor 21 only.

Radially disposed fins 26 between the turns of worm 7 impart to thepowdered solid fuel a rotatory motion in addition to the translational 9movement which aids in the picking up of the fuel by the air from ducts18. The motion of propeller 20 increases the turbulence of the airfuelmixture in the mixing chamber 14.

It will be understood that the above description and accompanyingdrawing comprehend only the general and preferred embodiment of myinvention, and that various changes in construction, proportion andarrangement of parts may be made within the scope of the appended claims19 without sacrificing any of the advantages of my invention.

The herein described invention may be manufactured and used by or forthe Government of the United States for governmental purposes 9 withoutthe payment to me of any royalties thereon.

Having thus described my invention, what I claim is:

l. A fuel burner comprising a body having a 1 5 longitudinal bore, amixing chamber, a nozzle chamber, and a plurality of ducts from theexterior of said body extending tangentially to said bore and openinginto said bore adjacent said mixing chamber; a shaft having alongitudinal duct therein mounted in said bore, a closure for an end ofsaid bore through which said shaft extends, a thrust collar on saidshaft on each side of said closure, a worm on said shaft, means tosupply solid fuel to said worm, a stub shaft on said shaft, a propellermounted on said stub shaft between said mixing chamber and said nozzlechamber, a burner for fluid fuel on said stub shaft operativelyconnected to the duct in said shaft,

' a Wind-box enclosing the outer ends of said plurality of ducts, meansto supply liquid fuel to the duct in said shaft, and a prime moverconnectible to said shaft.

2. A fuel burner comprising a body having a longitudinal bore, a mixingchamber, a nozzle chamber, and a plurality of ducts from the exterior ofsaid body extending tangentially to said bore and opening into said boreadjacent said mixing chamber; a shaft having a longitudinal duct thereinoperatively mounted in said bore, a worm on said shaft, means to supplysolid fuel to said worm, a propeller disposed between said mixingchamber and said nozzle chamber, and operatively connected to saidshaft, means to supply air to said tangentially extending ducts, meansto supply liquid fuel to the duct insaid shaft, and a liquid fuel burneroperatively carried by said shaft and connected to the duct in saidshaft.

3. A fuel burner comprising a body having a longitudinal bore, a mixingchamber, there being a plurality of ducts from the exterior of said bodyextending tangentially to said bore and opening into said bore adjacentsaid mixing chamber; a shaft rotatably mounted in said bore, a wormcarried by said shaft, means to supply fuel to said worm, means tosupply air to said tangentially extending ducts, and means drivablebyair from said ducts to rotate said shaft.

4. A fuel burner, comprising a body having a chamber therein, means tointroduce comminuted solid fuel into said chamber, means having parts incommon with the aforementioned means to introduce liquid fuel into saidchamber, means to introduce air into said chamber at points laterallyand rearwardly of the point of introduction of the liquid fuel and toimpart to said air movement having one component tangential and anothercomponent parallel to the direction of motion of the fuel beforeintroduction into said chamber and means operable by said air to driveelements of both of said fuel introducing means.

5. A fuel burner comprising a body having a longitudinal bore, a mixingchamber, there being a plurality of ducts from the exterior of said bodyextending tangentially to said bore and opening into said bore adjacentsaid mixing chamber, a shaft rotatably mounted in said bore, said shafthaving a longitudinal passage therethrough, a worm carried by saidshaft, a liquid fuel dispersing device on said shaft in communicationwith said passage, means to supply comminuted solid fuel to said worm,means to supply liquid fuel to said passage, means to supply air underpressure to said ducts and means operable by said air to drive said wormand said liquid fuel dispersing device.

6. A fuel burner, comprising a body having a longitudinal bore, a mixingchamber, there being a plurality of ducts from the exterior of said bodyextending tangentially to said bore and opening into said bore adjacentsaid mixing chamber, a shaft rotatably mounted in said bore, said shafthaving a longitudinal passage therethrough, a Worm carried by saidshaft, means to supply solid fuel to said worm, a liquid fuel dispersingdevice on said shaft in communication with said passage, means to supplyair under pressure to said ducts and means operable by air from saidducts to drive said worm and said fuel dispersing device, said devicebeing adapted to emit liquid fuel as a whirling spray substantially atright angles to the direction of forward movement of the air.

GUYSBERT B. VROOM.

